Do everything or sell it and get a better ski. If you're 240 pounds, you will not be very happy with the performance of a 550 for long, if at all. I've been on one that probably has no original parts left on it and its not very amusing. I'm the same size as you are. I'd get it running and get into a ski with more engine. If that's not an option, start with a pipe and impeller. But you'll be surprised how quickly you spend enough that you could have bought a better ski.